Orange Otocinclus
Orange Otocinclus (Nannoptopoma sp. ‘Peru Orange’), also known as the Orange Zebra Otocinclus or Robocop Otocinclus, is one of the most visually extraordinary algae-eating catfish available anywhere in the hobby. The vivid orange and dark brown zebra-like banding is unlike any other otocinclus relative, and the addition of a striking red ring around each eye makes this fish immediately recognizable. It is genuinely rare in the trade and commands significant attention from collectors.
Feeding & Care Tip: Live algae growing on the aquarium glass, plants, and hardscape is the single most important food source for Otocinclus — a tank without established algae growth will not sustain these fish regardless of what supplemental food is offered. Allow biofilm and green algae to develop on surfaces before adding otos, and do not over-clean the aquarium. Supplement with Hikari Mini Algae Wafers placed directly on the glass or substrate, and offer blanched vegetables — zucchini, cucumber, or spinach — 2–3 times per week. Remove uneaten vegetable matter within 24 hours to prevent water quality issues. The Orange Otocinclus spends considerable time grazing on submerged driftwood as well as plant surfaces — ensure driftwood is present in the aquarium as both a feeding surface and refuge. This species can be more delicate than common otos and benefits from particularly stable water conditions.
Native to the upper Rio Nanay near Iquitos in Loreto, Peru — a blackwater tributary of the Amazon known for producing several unusual fish species. The Nanay carries soft, slightly acidic water. This species inhabits slow-moving to moderately flowing streams with abundant driftwood, submerged vegetation, and algae-covered surfaces. Previously listed under Hypoptopoma sp. in some sources — the correct genus is Nannoptopoma.
Otocinclus are schooling fish that are markedly more confident, active, and healthy in groups. A lone otocinclus is a stressed otocinclus — it will hide constantly, refuse supplemental food, and decline over time. Keep a minimum of six, and ideally eight or more. In a proper group they are bold, constantly grazing, and frequently seen resting together in clusters on broad plant leaves or the aquarium glass.
Otocinclus are notoriously sensitive during the transition from the wild to captivity — virtually all trade specimens are wild-caught, and the stress of collection and shipping leaves them vulnerable in the first weeks. Slow, careful drip acclimation over at least an hour is strongly recommended. A mature aquarium with established algae growth, stable water parameters, clean water, and good oxygenation gives newly arrived fish the best possible start. The Orange Otocinclus can be particularly delicate during the initial acclimation period — ensure an abundant food supply of established algae is present before introducing this species.
Care & Ideal Parameters
| Difficulty | Moderate — Advanced |
| Temperament | Peaceful — Community |
| Typical Adult Size | 2.0 inches (5 cm) |
| Min. Group Size | 6 minimum — groups of 8+ strongly recommended |
| Ideal Temp | 72–82°F (22–28°C) |
| Ideal pH | 6.0–7.0 |
| Ideal GH | 1–10 dGH |
| Ideal KH | 0–5 dKH |
| Primary Food | Live algae and biofilm (from aquarium surfaces); Hikari Mini Algae Wafers |
| Supplemental Food | Blanched zucchini, cucumber, or spinach — offered 2–3 times per week |
| Origin | Upper Rio Nanay, near Iquitos, Loreto, Peru |
| Notes | Also called Orange Zebra or Robocop Otocinclus. Extraordinary vivid orange and dark banding with red eye ring — unlike any other oto. Genus Nannoptopoma (previously listed as Hypoptopoma in some sources). Extremely rare. Driftwood in tank important. Can be more delicate than standard otos. |